The present invention relates generally to crop harvesting headers attachable to a combine to initiate the crop harvesting process and, more particularly, to a control mechanism for operably controlling the lifting and tilting of the header in response to the sensing of the ground relative to the header to permit the header to follow changing ground contours.
For some crops, such as soybeans, it is necessary to keep the cutterbar of the crop harvesting header as close to the ground as possible without permitting the cutterbar to impact into the ground. The lateral float attachment mechanism for combine headers described in U.S. Pat. No. 4,253,295, granted to Larimer J. Knepper on Mar. 3, 1981, provides the capability for the combine header to be pivotally rotated about a centrally located pivot axis. The provision of a tilt cylinder between the header cradle assembly and the feederhouse provides the capability of rotatably moving the header during the harvesting operation thereof.
A combination of the movements of the header lift cylinders operably interconnecting the combine frame and the header to provide a generally vertical movement of the header with the movements of the header tilt cylinder to provide a lateral floating movement permits the combine header to closely follow changing ground contours to maximize the efficiency of the harvesting operation for crops in which it is necessary for the header to closely follow the ground. It would be desirable then to provide a control mechanism to automatically control the operation of the header lift and tilt cylinders so that the combine header will follow change in ground contours without operator input.